WASHINGTON, Sept. 22 (UPI) — China leads the world in the annual tonnage of fish caught and consumed, a study of nations having the greatest impact on ocean ecosystems says.

The research, conducted by the University of British Columbia in collaboration with the National Geographic Society and The Pew Charitable Trusts, ranks the Top 20 nations having the greatest impact through catching or consuming marine wildlife, a society release said.

China’s top ranking is because of its enormous population, despite its very low per capita consumption, the study said.

Japan is high on the list, a result of its rate of consumption — often by importation — of fish rather than its catch.

The United States comes in third in both catch and consumption, due to its relatively large population and tendency to eat top predator fish such as Atlantic salmon, the study found.

Much of the world’s catch is being purchased by wealthy nations for their people; poorer countries simply can’t afford to bid for high-value species, the study says.

World demand for seafood has sent fishing fleets into every fishing ground in the world, the researchers say.

A report by the World Bank and the U.N. Food and Agriculture Organization suggests that even if the number of boats, hooks and nets now used were cut by half, the world would still end up catching too many fish to be sustainable.

The scientists favor treaties among nations setting seafood-consumption targets as well as ocean havens to safeguard resources.

“Barely one percent of the ocean is now protected, compared with 12 percent of the land,” National Geographic Ocean Fellow Enric Sala says, “and only a fraction of that is fully protected.”